Download presentation

Presentation is loading. Please wait.

1
**Grade 9 Geography Mapping Skills – Map Scale**

Maps are very useful tools for locating things, determining direction or calculating distances. What? How do you calculate a real or actual distance from a paper map?

2
**Grade 9 Geography Mapping Skills – Map Scale**

Calculating real distances… You need two things from your map AND a mathematical formula to determine real distances: Map Distance – The measured distance on the map Scale – A ratio (i.e., each centimetre on the map is how far in real life Formula – MD/GD = scale where GD is Ground Distance (the real or actual distance)

3
**Grade 9 Geography Mapping Skills – Map Scale**

Map Distance (MD) With a ruler, you need to measure the distance ON THE MAP from your starting point to your finishing point. The example shows a trip starting in Istanbul and finishing near the border with Iran. With a ruler, measure the line. This is the distance on the map or Map Distance (MD)

4
**Grade 9 Geography Mapping Skills – Map Scale**

Scale is located on the map…usually along a bottom edge Scale is a statement of the relationship between distances on a map (i.e., Map Distance (MD)) and distances in real life (i.e., Ground Distance (GD)). As you know, a drawing made according to the scale will be an exact copy of the real object…only smaller. Scale is always presented as a ratio on a map. For example, scale is given as 1:25,000,000 which means 1 cm on a map is 25,000,000 cm in real life (or 250 km)

5
**Grade 9 Geography Mapping Skills – Map Scale**

Formula The formula for calculating the real distance (i.e., Ground Distance (GD)) is a ratio. If you know Map Distance (MD) and scale, you can “somehow” combine them to calculate GD. MD / GD = scale

6
**Grade 9 Geography Mapping Skills – Map Scale**

MD / GD = scale Example Scale is 1:37,000,000 or 1 cm = 370 km or 1 / 370 MD = 10.2 cm What is Ground Distance (GD)? MD / GD = 1 / 370 Let GD = x 10.2 / x = 1 / 370 x = (10.2)(370) = 3,374 The Ground Distance is 3,374 km

7
**Grade 9 Geography Mapping Skills – Map Scale**

MD / GD = scale Try one Scale is 1:25,000,000 or 1 cm = 250 km or 1 / 250 MD = 13.2 cm What is Ground Distance (GD)? MD / GD = 1 / 250 Let GD = x The Ground Distance is 3,300 km …right?

Similar presentations

Presentation is loading. Please wait....

OK

Using cartoons to draw similar figures

Using cartoons to draw similar figures

© 2017 SlidePlayer.com Inc.

All rights reserved.

Ads by Google

Ppt on recycling of waste plastic Ppt on uninterruptible power supply Ppt on principles of peace building solutions Ppt on javascript events click Ppt on cross site scripting prevention Ppt on communist party of india Ppt on entisols Ppt on indian textile industries in turkey Sap procure to pay ppt online Ppt on holographic display technology